John Kiely, the owner of Allied Cleaning Service in Manhattan, has encountered more than his fair share of office refrigerators during 40 years in the business. "If you can wear a mask, sometimes you'll be O.K.," he says. "But sometimes the stench is just too much. It'll make you light-headed. I've actually been scared a few times. Now I know what a decomposing body smells like."

Anyone who's shared a refrigerator with co-workers knows the sensation. Take a peek inside your company's communal fridge, and you'll come across some of the most pernicious sights this side of a Roger Corman movie: Saran-wrapped tuna salad sandwiches that seem to have a pulse, leftover moo shu pork in the early stages of evolution, and cartons of half and half with the consistency of white lava.

"My favorite is when they won't throw out a meal because it has sentimental value," he says. "Usually because it was made by their mom or a new girlfriend. I want to tell them: 'You know that new girlfriend you've got? I hope you're not thinking about marrying her for her cooking skills. Because let me tell you, her food stinks!' "

Office kitchenette horror stories have become noticeably menacing during the current recession; 70 percent of Americans, some likely looking to save money, are eating at their desks, according to an American Dietetic Assn. (ADA) survey of office workers. Longer lines for the break-room microwave increase the potential of soon-to-be-forgotten, bacteria-collecting leftovers in the fridge. This translates to increased health dangers. According to a study conducted by the ADA and ConAgra Foods, 44 percent of office refrigerators are cleaned once a month and 22 percent are cleaned only once or twice a year. Next time you're looking for a relatively bacteria-free place to store your lunch, consider that the bathrooms in your office are probably cleaner than the fridge.

According to the Agriculture Dept., the foods most likely to turn your office refrigerator into The Hurt Locker are casseroles, cold cuts, poultry, and the evil dairy twins: yogurt and sour cream. "One of the worst problems is food left in the fridge that everyone is encouraged to eat, like leftovers from an office meeting or group lunch," says Alice Henneman, a registered dietitian with the University of Nebraska-Lincoln Extension. "Who knows how long they sat out before they were refrigerated? I am aware of one company where over 30 people became sick because leftover food in a deep container didn't cool fast enough."

In some cases, decaying food is the least of the problem. Henneman, who has devoted much of her career to studying this occupational hazard, surveyed people on the worst things they'd encountered in office refrigerators. "The two scariest examples were human stool samples stored in the same refrigerator as employee lunches," she says, "and cow manure samples refrigerated next to food items."

She concedes that the stool samples "probably came from some type of company involved with laboratory procedures; there was no mention of any workers getting sick." Still, it's a precedent for anybody who's ever taken a long whiff of their office refrigerator and muttered, "What smells like crap in here?"

Co-workers who take it upon themselves to rid fridges of suspicious foodstuffs could be asking for trouble — physical and legal. Last year at an AT&T call center in San Jose, a helpful employee decided that somebody really ought to clean the company fridge. When she cracked it open, noxious fumes sent seven of her co-workers to the hospital and forced authorities to evacuate the building. "It was like a brick wall hit you," employee Robin Leetieh later recalled about the stench. Guys in hazmat suits were called in to clean up the mess. In 2007, the University of Texas ordered the "aggressive cleaning" of a messy chemistry professor's office, including his personal refrigerator. The professor sued, and the 5th U.S. Circuit Court of Appeals came down in his favor. It ruled that all "government employees must receive adequate notice before their personal belongings can be tossed out." Including, apparently, their leftovers.

Do the same rules apply to your co-worker's long-forgotten and increasingly toxic tuna casserole? Dennis P. Ortwein and J. Stephen Kreglow, Pennsylvania trial lawyers who share an office fridge, don't think throwing out a fellow employee's tuna casserole is grounds for legal action. If an oversensitive co-worker does complain when his or her lunch cum science experiment has gone missing and threatens to sue, "the damages are probably nil," says Kreglow. "What is a moldy tuna casserole worth?"

Some companies are coming up with creative solutions to stave off such predicaments. Google and PepsiCo have introduced organic corporate vegetable gardens, where employees can harvest their own lunch rather than fill the break-room refrigerator with food they've brought from home and will inevitably abandon. Then there's the Stackable Office Fridge, the brainchild of a New York industrial designer named Spencer Schimel. Though it has yet to reach the manufacturing phase, this Lego-style stack of mini-refrigerators—which vary in size from 6 in. by 6 in. to 12 in. by 12 in. — could allow your co-workers to have their own individualized lunch storage space.

"An important problem addressed in my design, where I believe most of the problems stem from, is personal accountability," says Schimel. "Because the office refrigerator is unowned by any individual, no one feels responsibility to take care of it, and certainly no one wants to take time out of his or her busy workday to do so."

Schimel isn't the only industrial designer focused on the refrigerator problem. Denmark's Innovation Lab is working on a refrigerator that records its contents through a touchscreen interface and bar code scanner. You'll receive a text or e-mail when an item reaches its expiration date. South Korea- based designers Yoon Jung Kim and Jong Rok Lee have come up with a refrigerator that features a door that becomes transparent with the push of a button. For distrustful employees who want to keep their yogurt on them at all times, German designer Sebastian Bertram has come up with a design for a backpack fridge, which is exactly what it sounds like.

In the meantime, there are still fridges to be cleaned. According to Martin Friedman, the owner of Blue Chip Cleaning Services in New York, hosing down the office fridge is not necessarily part of their job description. "Our standard rate only includes the exterior of appliances," he says. "Not the inside of the fridge. If they want that included, we'll bill them with a separate invoice."

Friedman's pricing formula takes into account square footage, cleaning frequency, and "population density." If your company is willing to pay extra, Blue Chip cleaners will take a blitzkrieg approach to sterilizing the refrigerator. Everything goes, with extreme prejudice, for a cost of up to $5,000 per month. "Sometimes the customer asks us to empty out the entire refrigerator, wash everything down, and then sort through their stuff and put anything that's still edible back in," Friedman says. "We don't do that. We'll use common sense. If there's an unopened bottle of soda, that obviously goes back. Beyond that, we're not going to make a subjective judgment call. If it's in there, it's garbage."